EP1344477B1 - Device for producing frothed milk for cappuccino - Google Patents

Description

The invention relates to a device for producing milk foam for Cappuccino according to the preamble of claim 1.

In such a known device, with an espresso machine is in communication and uses its steam generator is downstream one Steam supply arranged a nozzle assembly with a vacuum chamber, into which a steam nozzle opening is opened (EP-A-0 858 757). At the remote from the steam nozzle opening vacuum chamber outlet the vacuum chamber is approximately conically tapered and flows into a single hole as a calming section. In a cylindrical Section of the vacuum chamber between the steam nozzle opening and the negative pressure chamber outlet opens a supply line of an air-milk mixture. The premixing chamber is in particular cylindrical with a opposite the supply of the air-milk mixture larger diameter formed and connected to an air duct and a milk supply line. In this premixing chamber, an air-milk mixture is first formed, which flows into the vacuum chamber. There, steam is added, which also generates the negative pressure in the vacuum chamber. That by resulting steam-air-milk mixture then flows through the calming section, in which it is compressed and calmed so that it is in the desired consistency as milk foam emerges from the calming section. Preferred is a diameter / length ratio of the single bore, which forms the calming section, from 1:10.

To a good calming effect of the steam-air-milk mixture with sufficient To achieve throughput, the calming distance is in relation to the other elements of the device, including the dimensions of the vacuum chamber, relatively long.

Also known is a coffee filter holder with a coffee filter to milk coffee to produce with a fine-pored foam layer (WO 97/39668 A). In The filter holder can be inserted a coffee sachet, whose Upper side and bottom consist essentially of filter paper. Below of the coffee serving bag is a slotted separating plate arranged so that between her and the bottom of the coffee serving bag a free space is formed. Below the slotted intermediate plate forms the cup-shaped Coffee filter holder a space above a floor, the two Having outlet openings. Each of the outlet openings is in four partial openings each of which has a flow surface with a diameter of for example 1 - 5 mm forms. The diameter can be the outlet opening total about 6 mm. - If through the filter bag Brewing water is pressed, builds up in the free space above the slotted plate a fluid pressure on which coffee extract through push the slotted plate into the space in which bubbles are created. Only bubbles can flow out of the coffee filter holder, the smaller ones Have dimensions as the outlet openings or their partial openings. - Thus, it is not a generic device for Production of milk froth for cappuccino with a downstream one Steam supply arranged nozzle assembly with a mixing vacuum chamber, from the output steam-air-milk mixture with so high Flow energy exits that this must be calmed to one To reduce or avoid milk froth destruction. Rather have the known outlet openings only a screening effect to unwanted bubbles to retain large dimensions. This does not happen a length or distance to cover the mixture in the outlet openings Has.

The prior art also includes a milk frothing device, with the Steam, milk and air are intimately mixed (US-A-5 423 245). For this purpose, a mixing assembly is provided, with each by a Flow path initiated steam, milk and air matched be by adding milk and air through venturi action of a jet of steam be sucked. The matched mixture ingredients become then in a vortex chamber attached to the assembly further intimately. A delivery tube for dispensing the milk foam is transverse to a horizontal major axis of the assembly at the vortex chamber mounted oriented downwards, with the main axis of the assembly lies in the direction in which the steam flows into it. It is done by it a deflection of the flow direction and a further attenuation the flow energy of the steam. A cavity in the delivery tube is by a down-tapered laminator sheet with two flat surfaces divided into two chambers, one of which is a recess opposite a Laminatorblechebene, which the formation of a Bladder surface of the frothy milk flowing down the delivery tube should prevent. The planar surfaces of the laminator sheet are intended for a columnar drain to provide a discharge opening, wherein on the lower end of the laminator sheet, the drain is tied together. - According to Figures 3 and 4, the length of the two chambers in the delivery tube relatively small, but its clear cross-sectional area too large, for a sufficient sedative effect on the flowing milk foam especially if this delivery tube is directly attached to a Output of a mixing vacuum chamber would be used in the a steam nozzle arrangement is opened.

The latter also applies to a known separating plate, which in a cylindrical Interior of a so-called emulsifying chamber with a discharge opening protrudes, wherein tangentially to the emulsifying an approach with a through a steam flow by means of Venturi effect sucking milk and air Suction chamber is arranged (EP-B-0 195 750). In the emulsifying chamber should the resulting from the suction chamber mixture into a turbulent flow be offset, which is then released from the discharge opening. - The The above-mentioned separating plate is intended to serve the steam, milk and air particles to mix better and a rotation of the mixture with too high release rate to prevent.

Finally, a device for producing milk foam belongs to Cappuccino with a nozzle arrangement and a vacuum chamber for Prior art, in which an interior of the nozzle assembly below with a vane assembly is partially completed to the outside (DE-A-197 05 633). An inserted into the vane assembly guide pin, the down into a lower section of a swivel protrudes, should a plant emerging from the vane assembly Milk foam and cause a good flow behavior. Despite the leadership pin However, it is only a single outlet channel in the vertebral.

The present invention is therefore based on the object, a compact Manufacture device of the type mentioned production low, with a steam-air-milk mixture in the desired consistency is formed as a milk foam.

This object is achieved by an embodiment of the device with the features of claim 1, in particular its characterizing Partly solved.

Thereafter, the calming section consists of at least 3 calming channels, which are arranged in parallel in terms of flow, by their inputs the vacuum chamber outlet communicate with each other, wherein the outputs of the calming channels are all open and thus discharge openings for the formed steam-air-milk mixture or the milk foam represent. These are the steam-air-milk mixture, which is generated in the vacuum chamber, at the output in one of the number the number of partial flows corresponding to the calming channels is divided, wherein the diameter of each of the calming channels is relatively small is such that their length to achieve a desired diameter / length ratio, that for the compression and calming of the steam-air-milk mixture can be reached, can also be relatively small, that is, the component comprising the calming channels can be compact. In addition, the calming channels are particularly compact Arrangement spatially arranged substantially parallel.

They are manufactured favorable from a filling core, which is separated from the nozzle assembly manufactured and then downstream of the vacuum chamber is inserted into the nozzle assembly.

In spite of compact, short training of the calming section the desired To obtain consistency of the vapor mixture, which as Milk foam emerges from the calming section, should the clear diameter each sedimentation channel does not exceed an amount resulting from the diameter / length ratio of the calming section from 1 to at least 10, total divided by the number of calming channels, from which the calming section is composed.

According to claim 2, the at least 3 flow-parallel calming channels with mutually equal flow cross sections and expediently provided in mutually equal intervals.

The mixing process of the steam-air-milk mixture, which from the mixing Vacuum chamber flows, is already entering the calming channels completed, especially as no power tube of a calming channel communicates with a flow tube of an adjacent calming channel stands. For the latter reason is in the calming channels achieved an effective sedation of the mixture. The division of the calming section into several channels, each with a much smaller one Cross-section against a single calming channel also has the Advantage that this arrangement acts as a bubble screen, which is the leakage from during the mixing process in the vacuum chamber resulting prevents larger foam bubbles and thus to a particularly fine-pored and stable milk foam contributes.

For the production, but also for maintenance, it can be favorable, if according to claim 3, the calming channels outside of the cylindrical filling core coaxial with its rotational symmetry axis and at equal circumferential distances are formed. It should be noted that after assembly of the filler core whose rotational symmetry axis with that of the cylindrical Space of the nozzle assembly matches.

In a further development according to claim 4, the filling core with a cylindrical Main section and one after mounting in the vacuum chamber be formed facing this domed end, wherein the outside from the cylindrical main section formed calming channels continue on the dome-shaped end, and there elliptically recessed run. The recess thus extends in the direction of the central axis or rotational symmetry axis of the filling core. This will be a uniform achieved good flow introduction into the calming channels.

Preferably, the vacuum chamber outlet is simply according to claim 5 from the fluidly parallel calming channels themselves, i. there are no between the vacuum chamber and the calming channels inserted further flow-influencing structures.

For this purpose, the device is low-production in detail according to claim 6 formed with a cylindrical space in the nozzle assembly, the mixing vacuum chamber and the output of which constituent calming channels includes.

Specifically, according to claim 7, the filling core in a lower portion of the cylindrical space can be used in the nozzle assembly.

Another advantage is that the filling core, for example for cleaning purposes or for replacement, just from the lower section of the cylindrical space can be removed.

As mentioned above, the mixture of steam-air-milk mixture is complete, when it enters the calming channels. To this mixing serves except the premix chamber, an embodiment of the device according to claim 9, wherein the nozzle opening in the nozzle arrangement at a top, first end of the vacuum chamber is arranged, which is the lower, opposite the second end of the vacuum chamber, at which the vacuum chamber outlet located with the calming channels. In this arrangement the nozzle opening is a mixing of the air-milk mixture, the premixed via a preferably nozzle-shaped supply line into the vacuum chamber is sucked in, with the emerging from the nozzle opening Steam over a large distance of the vacuum chamber.

Figur 1

einen Längsschnitt durch eine erste/bevorzugte Ausführungsform des erfindungswesentlichen Teils der Vorrichtung zur Erzeugung von Milchschaum für Cappuccino,

Figur 2

eine Aussicht auf die erste Ausführungsform von unten und

Figur 3

einen Längsschnitt durch eine zweite Ausführungsform.

Die erste Ausführungsform gemäß Figur 1 umfaßt eine Düsenanordnung 1, die einen zylindrischen Raum 2 umschließt, der an einem unteren Ende 3 ursprünglich offen ist. An einem dem unteren Ende 3 gegenüberliegenden oberen Ende 4 weist der dort im wesentlichen geschlossene zylindrische Raum 2 strömungsmäßig stromabwärts einer Dampfzuleitung 5 eine Düsenöffnung 6 auf. Das obere Ende 4 wird auch als das erste Ende bezeichnet und das untere Ende 3 als das zweite Ende. - Die Düsenanordnung 1 mit dem zylindrischen Raum 2 und der Düsenöffnung 6 ist im wesentlichen rotationssymmetrisch um eine Rotationssymmetrieachse 8 ausgebildet.Two embodiments of the invention are explained below with reference to a drawing with two figures. It shows:

FIG. 1

a longitudinal section through a first / preferred embodiment of the invention essential part of the device for producing milk foam for cappuccino,

FIG. 2

a view of the first embodiment from below and

FIG. 3

a longitudinal section through a second embodiment.

The first embodiment according to Figure 1 comprises a nozzle assembly 1, which encloses a cylindrical space 2, which is originally open at a lower end 3. At an upper end 4 opposite the lower end 3, the cylindrical space 2, which is substantially closed there, has a nozzle opening 6 downstream of a steam feed line 5. The upper end 4 is also referred to as the first end and the lower end 3 as the second end. - The nozzle assembly 1 with the cylindrical space 2 and the nozzle opening 6 is formed substantially rotationally symmetrical about a rotational symmetry axis 8.

In the cylindrical space 2 opens near the upper end 4 a Supply line 9 for an air-milk mixture, which generates in a premixing chamber is whose output is connected to the supply line 9. In the premix chamber end a milk supply line and an air duct.

In a subsequent to the lower end 3 of the cylindrical space 2 upwards Section 7, also referred to as the lower section, is a Fill core 10 is inserted. The filling core is a substantially cylindrical Main section 11 and an upper dome-shaped portion 12 is formed. From both sections 11 and 12 of the filling core are six continuous calming channels 13 to 18 formed, concentric with the rotational axis of symmetry 8 and at equal circumferential distances from each other, see Figure 2. As Figure 1 shows in detail, the flow channels, there are 14 and 17, formed over the cylindrical main portion 11 with the same radial depth and over the dome-shaped portion 12 slightly elliptical to the central axis or rotational symmetry axis 8 recessed. The calming channels 13 to 18 are thus fluidly and substantially geometrically parallel arranged to each other.

If in the described nozzle assembly 1 via the steam supply line. 5 Steam is supplied, arises as a result of the illustrated embodiment of the nozzle assembly 1 in an upper portion of the cylindrical space 2 above the through the filling core 10 filled lower portion 7, a negative pressure due the effluent from the nozzle opening 6 steam. The upper section is thus a vacuum chamber 19, on the one hand at the upper end 4 of the cylindrical Chamber 2 and on the other hand on a top 20 of the core 10th is largely completed. The negative pressure in the vacuum chamber 19 propagates via the supply line 9 in the premixing chamber 25, in which therefore Milk and air are sucked and mix in this. The result resulting air-milk premix is via the nozzle-shaped supply line 9 in sucked the vacuum chamber 19, where they are with the in the vacuum chamber 19 incoming steam up to the top 20 of the filling core 10 intimately a steam-air-milk mixture mixed. The vacuum chamber 19 is therefore also referred to as mixing vacuum chamber.

The formed with the air-milk premix in the vacuum chamber 19 Steam-air-milk mixture needs no further mixing, but only one Calming and partial compaction to make it as milk froth for cappuccino desired consistency from discharge openings of the device to the outside flows. The discharge openings are through the open calming channels 13 to 18 at the lower end 3 of the nozzle assembly 1 and the cylindrical Room 2 is formed.

As a result of the same formation of the clear cross sections of the calming channels 13 to 18 and their symmetrical arrangement to the rotational axis of symmetry 8, all calming channels become practically even with steam-air-milk mixture streams directly from the mixing vacuum chamber 19 charged. These steam-air-milk mixture substreams are effectively calmed and compressed in the individual calming channels, because their diameter or clear cross sections in relation to their Length extending over the cylindrical main section and the dome-shaped Section of each calming channel extends, are small. To define the Diameter or cross sections can actually shaped, for example semicircular or square cross sections of the calming channels be approximated by imaginary circular cross sections.

It has been found that by the embodiment shown in FIGS. 1 and 2, in which the calming channels 13 to 18 directly an output form with discharge openings of the vacuum chamber 19 to the outside, a fine-pored and very stable milk foam is produced. This can be the throughput be greater overall than before by the calming channels. The bigger one Throughput has the advantage that the flow rate at the output the calming channels are lower and one at the end of the foaming occurring residual steam jet generated and under the discharge openings Trapped foam less affected. On the other hand, the number the calming channels are reduced with constant sizing, if a lower throughput is desired.

The embodiment of Figure 1 has the manufacturing advantage that the mixing vacuum chamber simply from a section of the continuous cylindrical space 2 of the nozzle assembly 1 with a substantial degree is formed at its upper end, the output side uncomplicated largely completed by the filling core 10 used in it becomes. The nozzle-shaped supply line 9 is preferably through an air-milk nozzle 26 realized at the vacuum chamber 19.

The illustrated in Figure 3 second embodiment of the device is different from the first embodiment by the formation of the nozzle assembly 21 with a substantially cylindrical vacuum chamber 22, the an inner cone-shaped portion with a central opening 23 above the top 20 of the filling core 10 has. The filling core 10 is as well as the one shaped in Figures 1 and 2. The filling core 10 is in a likewise dome-shaped portion 24 which is disposed below the opening 23, inserted. Since the calming channels 13 to 18 of the filling core 10 here below connect the cone-shaped portion directly to the opening 23, this provides a beginning of a calming section through the parallel calming channels 13 to 18 is formed. The same as in the above first embodiment mixing vacuum chamber 22 thus also has a Exit with calming channels 13 to 18, which the discharge openings form at its lower end.

Also in this embodiment, the steam-air-milk mixture with the Air-milk premix produced in the mixing vacuum chamber 22, of the nozzle-shaped supply line 9 with the air-milk nozzle 26 to the vacuum chamber 22 leads. Then take place in the Unerdruckkammerausgang, consisting of the opening 23 and the calming channels 13 to 18, only another compression and sedation of this mixture, which as Milk foam from the formed by the below calming channels Dispensing openings is discharged to the outside.

reference numerals

1

nozzle assembly

2

cylindrical space

3

lower second end

4

upper first end

5

steam supply

6

nozzle opening

7

lower section of the cylindrical space

8th

Rotational symmetry axis

9

supply

10

filling core

11

cylindrical main section

12

domed section

13

calming conduit

14

calming conduit

15

calming conduit

16

calming conduit

17

calming conduit

18

calming conduit

19

Vacuum chamber (upper portion of the cylindrical space)

20

top

21

nozzle assembly

22

Vacuum chamber

23

opening

24

domed section

25

premix

26

Air-milk nozzle

27

air duct

28

Milk flow regulator

29

milk line

Claims (10)

1. Apparatus for proceeding frothed milk for cappuccino comprising a nozzle arrangement (1, 21) disposed downstream of a steam supply line, having a mixing low-pressure chamber (19, 22) into which a steam nozzle opening (6) is opened and into which discharges a feeder (9) of an air-milk mixture from a premixing chamber, said premixing chamber being connected with an air channel and a milk feeder, and having an calming portion at a low-pressure chamber outlet, wherein one end of said calming portion forms at least one discharge opening for discharging a steam-air milk mixture to the outside,
   characterized in that said calming portion comprises at least three calming channels (13 through 18) parallel in flow direction each forming at one open end a discharge opening for discharging a steam-air milk mixture partial flow to the outside,
   that said calming channels (13 through 18) are formed out, substantially spaced in parallel relative to each other, from a substantially cylindrical filling core (10) which is inserted downstream of said low-pressure chamber (19, 22) into said nozzle arrangement (1), and
   that the inside diameter of the cross section of each of said calming channels (13 through 18) is dimensioned in a relation to the length thereof which amounts to 1 to at least 10, divided in total by the number of calming channels (13 through 18).
2. Apparatus according to claim 1,
   characterized in that said at least three calming channels (13 through 18) are provided as to have substantially equal flow cross sections relative to each other and equal distances relative to each other.
3. Apparatus according to at least one of claims 1 and 2,
   characterized in that said calming channels (13 through 18) are formed-out at the outside from said substantially cylindrical filling core (10) at equal circumferential distances and substantially in parallel relative to a rotational symmetry axis (8) of said filling core.
4. Apparatus according to at least one of claims 1 to 3,
   characterized in that said filling core (10) is shaped as having a cylindrical main section (11) and a dome-shaped end (12) facing said low-pressure chamber (19, 22), and that said calming channels (13 through 18) formed out from said cylindrical main section extend over said dome-shaped section (12) and are recessed in it in an elliptical fashion.
5. Apparatus according to at least one of claims 1 to 4,
   characterized in that said low-pressure chamber outlet consists of said calming channels (13 - 18) disposed in parallel relative to the flow direction.
6. Apparatus according to at least one of claims 1 to 4,
   characterized in that said nozzle arrangement (1) comprises a cylindrical space (2), that an upper end of said cylindrical space (2) except for the nozzle opening is closed, that at a lower end (3) facing said upper end (4) said cylindrical space (2) is closed except for said calming channels (13 through 18), wherein said calming channels (13 - 18) form the discharge openings at the lower open ends thereof, and that in the section of said cylindrical space (2) between said nozzle opening (6) and said calming channels (13 - 18) said mixing low-pressure chamber is formed into which joins the feeder (9) of the air-milk mixture from said pre-mixing chamber
7. Apparatus according to claim 6,
   characterized in that said filling core (10) is inserted into a lower section (7) of said cylindrical space (2) of said nozzle arrangement (1).
8. Apparatus according to at least one of the foregoing claims,
   characterized in that said calming channels (14 through 18) are disposed coaxially relative to a rotational symmetry axis (8) through said low-pressure chamber.
9. Apparatus according to one of the foregoing claims,
   characterized in
   said nozzle opening (6) in said nozzle system (1) is disposed at an upper end (4) of said low-pressure chamber (19, 22), which faces said lower end of said low-pressure chamber (2) at which the low-pressure chamber outlet having said calming channels (13 through 18) is disposed.
10. Apparatus according to one of the foregoing claims,
    characterized by
    a nozzle-like shape of the feeder (9) of the milk-air mixture.

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